1. Field of the Invention
The present invention relates to safely disposing of medical waste, particularly needles and the like, in a manner which minimizes the danger of transmission of infectious diseases. More specifically, this invention is directed to a disposal system and, especially, to such a system which comprises a receptacle for contaminated medical products of the type which comprise a hub, the products also typically including a needle, the system additionally comprising a holder which cooperates with the products so as to cause a product mounted to the holder to be automatically detached from the holder and deposited within the receptacle. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Related Art
A wide variety of blood collection/fluid injection devices are used by the health care industry. These devices include a hollow bored member, hereinafter a "hub", for transferring fluid materials via a cannula, hyopodermic needle or via the hub itself thereby providing a connective conduit for the fluid path. The hub may be tapered, and/or may be externally threaded or may have some other external configuration to faciliate and provide attachment means. These hub based devices include hypodermic syringes and blood collection/fluid injection systems. While hypodermic syringes normally have a fluid chamber integrally formed with the needle holder, blood collection/fluid injection systems typically include a needle holder having a hub detachably mounted thereon so that a needle is disposed at one end of the holder and a fluid collection tube may be inserted in the other end of the holder.
For both economic and safety reasons a wide variety of venipuncture devices has been developed. Economic factors have favored designs having associated holders which allow hub removal whereby reuse of the holder is permitted. Safety concerns, however, have pointed away from the use of such devices because the hub removal procedure creates an increased risk of inadvertent contact between the health care worker and a patient's bodily fluids and, particularly, an accidental needle stick. In recent years, increased concern about the transmission of infectious diseases, such as HIV and HBV, has renewed interest in developing safer methods and apparatus for disposing of infectious medical waste. Most of the development efforts to date have been directed toward simplifying the process of removing a hub from a holder while simultaneously minimizing the health care worker's contact with the "sharp" which is affixed to or integral with the hub. In particular, these efforts have been directed toward improving both hub retaining mechanisms and complementary hub removing means which are integrated with sharps disposal receptacles.
Sharps receptacles designed for removing a standard externally threaded hub from a holder typically possess a hollow base portion for receiving the detached devices, and a cover having various shaped slots, known in the art as unwinder apertures or unwinder slots, for engaging a hub during needle removal. To dispose of a previously used hub with attached needle using a conventional sharps receptacle, a health care worker must carefully position the hub in the appropriate slot and then grip and rotate the holder to unthread the hub so that it and the attached needle may fall through the slot into the underlying body of the receptacle. When using these devices, it is often difficult to tell when the hub has been fully unwound from the holder. Since the health care worker may be simultaneously performing other tasks, there exists a serious danger that a hub may "hang-up" and the associated needle inadvertently contact an unsuspecting health care worker. A further deficiency of prior art devices of the type being discussed stems from the lack of any product misuse prevention features. For example, the use of hubs which only appear to be compatible with a given unwinder slot may cause a malfunction. Where the hub is attached to a double-ended needle, i.e., a cannula, a further danger arises after the hub is disengaged from a holder because the hub may remain lodged in the slot, causing exposure of the upstanding posterior end of the cannula. In such a case, the user must physically handle the hub to remove it from the slot and permit the cannula hub assembly to drop into the sharps receptacle.
Aside from hub-engaging unwinder slots, other medical "sharps" removal schemes have been developed. These include the use of sharps receptacles having movable jaws which engage the standard externally threaded hub of a needle assembly. Such devices allow a user to unthread the hub/needle combination from a holder by (1) inserting the hub into a sharps box having such jaws; (2) operating the jaw mechanism to lock the hub; (3) rotating the holder to unthread the hub from the holder; and (4) releasing the locking mechanism to allow the now threadably removed hub and needle combination to fall into the sharps container base. While some sharps disposal containers of this nature can effectively remove threaded hubs, with associated needles or cannulas from holders, they are typically complex and costly devices, the complexity having a deleterious effect on reliability. Additionally, such sharps receptacles still require the health care worker to follow a relatively lengthy and complex manual hub-unwinding procedure. As with less complicated devices having unwinder slots, these receptacles periodically suffer from the problem of incomplete hub unwinding. Finally, safety is again compromised by the lack of any means for preventing operator misuse.
A similar style of disposal system, which has both increased safety and a simplified hub removal procedure, includes a sharps receptacle with an electric hub-unwinding mechanism. Sharps receptacles of this nature allow a health care worker to simply insert a holder having a hub/needle combination received therein into an aperture whereby the hub is unthreaded from the holder by means of an electric motor. Deficiencies associated with these mechanical sharps disposal systems include the facts that the receptacles are (1) very expensive to build and maintain; and (2) not easily transportable because they require some kind of electric power supply. Further, while incomplete hub unwinding is less of a problem with these systems, none of these power driven systems include any type of operator misuse prevention feature.
Finally, sharps disposal systems have been proposed wherein the sharps disposal container cooperates with a custom hub holder to effect needle release. Some of these proposed disposal systems are allegedly compatible with cannula assemblies having an externally threaded hub. While such a system would theoretically increase the safety of the "sharps" removal procedure, a rather complex series of steps would be required to achieve removal. Thus, increased safety is achieved at the expense of simplicity of operation. One proposed system for use with a custom holder requires that an adapter be placed on the hub, the hub of a cannula assembly for example, in order to make the cannula assembly compatible with the holder. The need for a hub adapter obviously results in a cost increase. Finally, neither the holder nor the sharps container of the proposed systems have any means to prevent a health care worker from using them with other, potentially incompatible, devices. Thus, safety is again sacrificed by the lack of operator misuse prevention features.
Co-pending U.S. Pat. App. No. 08/580,322, filed on Dec. 28, 1995, now U.S. Pat. No. 5,755,673, issued May 26, 1998 on continuation application Ser. No. 08/904,411 filed on Aug. 1, 1997, is directed to an improved holder for a fluid collection and/or injection system. That application has been assigned to the assignee of the present invention and the information disclosed therein is hereby incorporated by reference. The holder shown and described in application 08/580,322 possesses an actuation mechanism at one end of the holder. The actuation mechanism enables the mounting of the externally threaded hub of a cannula assembly on the holder and the maintaining of the attachment of the cannula assembly to the holder during use. Initially, the threaded hub will be threadably engaged by the actuation mechanism of the holder in the same manner as the hub/needle combination would be installed in any other medical device holder which accepts a threaded hub. Upon operation of an external actuator of the actuation mechanism, the hub is released from the actuation mechanism whereby the hub/needle combination will fall from the holder under the force of gravity. In one embodiment of the holder, the actuator is in the form of a push-button which is capable of being depressed by the operator's finger. Thus, this medical sharps holder configuration offers both compatibility with standard threaded hubs and a safe and simple means of removing a hub, particularly a hub which is integral with a cannula or needle, from the holder. However, while the holder of the aforementioned co-pending application represents a substantial advance in the sharps disposal field, some methods and apparatus of safely disposing of used hubs from such a holder are beyond the scope of the incorporated application. Thus, some aspects of the sharps disposal system of the present application represent improvements on the holder shown and described in the incorporated application.